Apparatus for making sand cores



Jan. 14, 1930. F. H. MOREHEAD 1,743,473A

APPARATUS FOR MAKING SAND CORES Filed Feb. B. 1928 2 She'ets-'Sheet 1 '3y @MWJWL Zar/2 ggfs'.

Jan. 14, 1930. F. H. MOREHEAD f 1,743,473

APPARATUS FOR MAKING SAND CORES Filed Feb. 8. 1928, 2 Sheets-Sheet 2 In 049/2601. 'n

Patented Jan. 14, 1930 UNITED STATESl FRENCH H. MOREHEAD, OF BOSTON, MASSACHUSETTS APPARATUS FOR MAKING SAND CORES Application led February 8, 1928. Serial No. 252,771.

My present invention relates to methods 'and apparatus for making sand cores for casting tubular articles such as pipe, hydrant barrels, columns and the like of the type referred to in my co-pending application Serial No. 252,770, led February 8, 1928.

As is well known to those skilled in the art,

cores for long articles cast in substantiallyl horizontal position are bent or distorted during casting by the pressure of the moltenl metal which tends to float the core. Attempts have been made to counteract this effect as for instance by subjecting the core after it is in place in the mold to stresses which tend to bend the core in the direction opposite to thatproduced by its tendency to float. The tendency of the core to float and thus be distorted can also be overcome by employing a core which is bent the right amount during its manufacture so that when the metal is poured the tendency to float brings it to the desired straight position. My present invention, therefore, has forits object a method and apparatus for making suitable bent cores rapidly and economically.

It is the object of the invention to produce by rotation cores adapted to overcome the above mentioned dificulties and which may be straight but not of circular cross sectionV or to produce bent cores which may or may not be of circular cross section, any of which may be uniform or variable in cross section from end to end.

In the practice of my present invention suitable core sand is shaped upon an arbor while the arbor is flexed by a suitable force applied thereto. Thereafter the arbor is permitted to straighten or return to its original condition and thereby flex the body of sand shaped thereon. By my preferred procedure the core sand is deposited on a rotating arbor and is trimmed by a suitable knife as the arbor is rotated, the arbor being iiexed or bent by a suitable mechanism. The

invention provides a simple and effectiveV method and apparatus for producing suitable cores as fast as straight ones and the cores can 1 be employed in ordinary molds without employing any means to bend them after they are placed in the mold, or to hold them against bending due to their tendency to float in the molten metal; therefore, casting with cores made in accordance with the process embodying my invention is'much simplified and cheapened. Tubular articles produced byV the use of the cores so made have a uniform cross section and therefore metal is saved. The number of defective articles which must be rejected is reduced and the articles have a longer life with no additional expense in manufacture.

Before explaining in detail the present invention, and the method or mode of operation embodied therein, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practised or carried out in various ways. Also-it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation, and it is not intended to limit the invention beyond the terms of theseveral claims hereto appended or the requirements of the prior art.'

The invention will be more clearly understood from the following description, in conjunction with the accompanying drawings, in which Fig. 1 is an elevational view partly in sec- Y tionof an apparatus embodying the invention;

Fig. 2 is a side sectional view of the same.

Fig. 3 is a sectional view taken on the line 3-8 of Fig. 2, and

Fig. 4 is an elevational view of the core j produced by the practice of the invention.

A suitable apparatus embodying my invention may comprise a suitable support 10 having a frame 11 extending upwardly near each end of the apparatus for rotatably supporting rolls 12 upon which a normally straight arbor 13 rests. A cross member 14 is piv- Voted at one end to the frame 11 and detachably mounted thereto, as. by a bolt 16 and a nut 17, at its outer end. A roll 15 is rotatably mounted in the cross member 14 so as to engage the arbor and hold the same ber 21 having a portion 22 forming part of la journal for an .eccentric or ,cam 23 .detachably mounted upon the arbor in any suitable manner, as by a set screw 241. Across member 24 is pivot'ally mounted at lone 'side of the top of each frame A20 and is detachably secured to the other side as by a nut 25 and bolt 26. A shaping knife 27 is secured, as by screws 28, to a cross member 29 connecting frames 11.

The arbor may be 4rotated by a mechanism v.at each end,including ashaft 30 provided at one end with a yspline or key 31 ada ted to `engage a slot or keyway 32 in the en s of` vthe arbor. The other yendV of the shaft 30 is connected by a universal joint 33 to a. shaft A34 rotatably mounted in the frame. The driving mechanism at each end of the arbor may lbe connected to operate in synchronism. For this purpose each shaft 34 may1 beprovided with a gear 35 operativelyconnected with a gear 36 near each end of a shaft 37 rotatably mounted in the frame. V*This lmechanism may be operated from any suitable source of power transmitted for example to a pulley 38 mounted upon the shaft 34.

A suitable hopper 40 is supported in any convenient manner, as by a frame 41, above the arbor 13 and is provided at its lower end with a chute 42 extending to a point close to the arbor. A riddle 43 is suspended within the hopper and is provided with upwardly extending arms 44 pivotally mounted upon shafts 46 secured in a frame 47 extending upwardly from the hopper. Y

In the manufacture of cores, power issupplied to rotate the arbor 13 and during its rotation the eccentrics 23 will cause bending` or lexure of the arbor 13. A suitable mixture of sand and binder is introduced into the riddle 43 and the latter is' vibrated, whereupon the sand and binder mixture passes downwardly through the hopper 40 and chute 42and is deposited upon the arbor is with Considerable impact. The sand will.

cling to the surface of the arbor due to the presence of the binder admixed therewith, and will accumulate upon the arbor until engaged by the effective edge of the shaping vknife 25. Theknife will shear off any excess of sand Vvand binder mixture and shape the same. The supply o f sand mixture is then out off andthe arbor rotated through one or two revolutions thereafter. The amount of ilexure of the arbor will be controlled by the f", apparatus, itfwill tend to straighten and f thereby impart a curvature to the accumulated sand mixture 46 to provide a crooked revolving arbor, flexing the arbor during its rotation, and shaping said mixture on the arbor by a knife as -the arbor rotates.

3. In an apparatus for making sand cores,

a rotatable arbor, means for `depositing a suitable sand mixture on the arbor, a knife for shaping said mixture, and acam acting -upon the arbor'to flex it.

4. In an apparatus for making sand cores, a rotatable arbor, mea-ns 4for depsositing a suitable sand mixture upon the arbor, a knife for shaping said mixture, means for rotatably supporting said arbor at spaced points, and

a Vcam acting upon said" arborat ay point Y spaced from saidlsupporting means `to flex the arbor. v

In testimony whereoffI Iaffix my signature.

FRENCH H. MOREHEAD. 

